Tractor



R. H. WHITE A ril 7, 1931;

TRACTOR Filed Sept. 10, 1927 4 Sheets-Sheet l @HQHQ b A w n QCQ INVENTOR v [Mia W I A ATTORNEY.

April 7, 1931. w T 1,799,878

TRACTOR Filed Sept. 10, 192'? 4 Sheets-Sheet 2 W 14- WSW H. WHITE April 1, 1931.

TRACTOR Filed Sept. 10, 1927 4-Sheets-Sheet 3 H M W S nk April 7, 1931.

R. H. WHITE 1,799,878

TRACTOR Filed Sept. 10, 1927 4 Sheets-Sheet 4 Patented Apr. 7, 19 31 UNITED STATES? PATENT or-rice BOLLIN H. WHITE, or CLEVELAND nnien'rs, on'ro My invention relates to tractors and relates partlcularly to tractorsof the track laying type.

I parts ofthe track and the rollers engaged by the track have heretofore often been subjected to severe stresses incidental to theuse of the tractor, large stones or other foreign articles become lodged on the upper surface of the ground run of the track and are thereby carried between the rollers and the track, making wedging engagement therewith and 'caus ing breakage of the track or the track rollers or parts supporting the same. An object of my invention, therfore, is to provide for the relief of stresses which other wise would set up strains in the track rollers or the parts supporting the same tending to break the same, or efi'ect strains causing distortion of the same. v

Another object of my invention is to provide means to relieve abnormal stresses otherwill be nevertheless wise exerted on parts of the tractor mecha nism comprising the track, Without interfering with the normal action of the track or its adjustment but which will come into action only upon the existence of conditions tendingto set up breaking stresses in the track and related parts.

Another object of my invention is to provide for the relief of stresses by a mechanism having a relatively constant resistance to the stresses set up overfthe prevailing range of operation which must be provided for in,

such mechanisms. Another object of my invention isto provide for the accomplishment of the aforesaid objects in a mechanism which is relatively inenpensive to make and maintain, but which continuously eficient in operation.v c.

Uther objects of my invention and the in vention itself will become apparent by reference'to the description of two embodiments of my invention and the drawings illustrating the same.

In tractors of the track laying type, the

\ v Application flled fleptember 10, 1927. Serial 1T0. 218,591.

Fig. 1 shows a side elevational View of a tractor embodying my invention;

Fig, 2 illustrates in vertical section the front roller and the mounting means therefor taken on line 22 of Fig. 1; I Fig. 3 illustrates, in approximately horizontal section, the apparatus of Fig. 2 and other apparatus cooperating therewith taken on line 33 of Fig. l;

Fig. .4 illustrates a fragment of atractor in which is incorporated a second embodiment pf my invention, the view being in side'eleva- 011; 9* 1 Fig. 5 is a yiew of the embodiment of Fig. 4 1n approximately horizontal section, the apparatus illustrated corresponding to that illlglstrate'd for the first embodiment in Fig. 3; an

Fig. 6 is a vertical view 6-6 of Fig. 5. I

Beferringfirst to the embodiment of my invention illustrated in Figs. 1 to 3, inclusive, of the drawings, in all of which I employ like reference characters to designate the same parts, at 2 Ishow a tractormain frame which supports the superstructure 1, comprising the cab, engine, the radiator, and the parts auxiliary thereto, all of which may be readily recognized from the showing of Fig. 1, or will be understood as being supplied. The main frame 2 is supported on a pair of latertaken on the line ally disposed track frames20 by means of Each track frame isiencircled by an endless chain track, which is engaged by a rearwardly disposed driving sprocket 8, having sprocket teeth 9, a forwardly disposed idler r roller 62 of a size preferably corresponding to that of the driving sprocket, and a plurality of relatively smaller rollers, such as those shown at 24, 25, 26 and 27, there'being, in the embodiment illustrated, seven of these small rollers, suitably journalled in the lower rtionof the track frame, for the purpose Lugs,

of carrying the weight of the tractor on the parallel rails, each are made up of aligned rail sections carried by the track link shoes 30 on their inner faces by upright webs 29, integrally joining the rails and track.

The track frames are oscillatable vertically, preferably upon the laterally projecting shaft ends 5, the integral bosses 4 of the track frame castings being suitably bored so as to make a good bearing flt upon the ends of the axle 5. as at 28, are adapted to carry a guard plate for the rollers in a manner similar to that shown in Fig. 4. The forward idler roller wheel 62 is journaled in a fork element generally indicated at and which is supported on the forward end of the track frame.

The above relative disposition of the parts is not uncommonly employed in the art and is sufiiciently well known as not to require a fuller description, and are duplicated on both sides of the machine.

Each of the track frames 20 is preferably formed with a flanged table top 21, the laterally projecting flanges adding to the rigidity of the frame, especially for resisting laterally dircctd stresses, and supports the fork 35, and a thrust element secured to it by bolts 46 passing through its base flanges.

The fork 35 comprises a base 31, depending channel guiding flanges 32 and upright webs comprising spaced roller supporting fork elements 77, each laterally braced by spaced upstanding webs 68, and spaced by a yoke web 69, which has the bored central boss 36.

The roller 62 is rigidly secured between two spaced flanged hub elements 63, by a plurality of bolts 64 passing through their peripheral flanges and the wheel. The wheel is provided with a pair of spaced rail rims 61 supported by a spoke portion comprising integral lateral skeleton sides and inter-- mediate spaced radially extending webs to form a skeleton wheel, not likely to entrap, but rather to pass extraneous articles, such as clods and stones through it.

Blocks 51 and 52 are secured by bolts 50 on the forks 77 and with complementary portions of the forks, provide a tapered axle receiving bore in which an axle 53 is mounted on the fork by its tapered end portions 54, which terminate exteriorly of the blocks in threaded ends 55. to which retaining nuts 56 are aflixed. A felt or other packing 72 is disposed intermediate outer tapered ends of the hub elements 63 and the walls of the recesses formed on the inner sides of the fork ends and blocks, to prevent egress of lubricant and ingress of dust relative to the axle bearings.

The axle is preferably formed with cylindrical bearing surfaces for the roller hubs 63, and aperipheral annular thrust bearing flange 66 of the axle is disposed intermediate the inner ends 67 of the hubs. An annular space 65 is provided peripherally of the flange 66 and may be packed with lubricant for lubricating the internal thrust bearing formed by contacting lateral surfaces of the inner hub ends 67 and of the flange 66. Such a bearing is very well protected from the ingress of dust and grit, which is quite injurious to other types of thrust bearings for tractor rollers hitherto commonly employed.

The thrust element 45 has a bored head 47 for the reception of a threaded thrust rod 85, screw threaded at 48 through the bore and adapted to make contact centrally within a centering recess on an outer face of a thrust disk 39. The thrust disk is heldby a bolt 38 screw threaded into a threaded recess 40 of its inner face, and projecting through a central portion of the fork 35, the head 41 of the bolt being retained within the yoke of the fork. A heavy helical compression spring 43 is held under heavy compressive stress between the yoke and an annular lateral flange 44 of the thrust disk 39. A boss 36 disposed centrally of the fork yoke and having an axial bore 37 through which the bolt 38 projects, extends slightly within the forward end of the spring to prevent its lateral displacement.

It is to be understood that I preferably accomplish the compression of the spring 43 prior to longitudinal adjustment of the rod 85, which is preferably accomplished after assembly of the fork 35, which carries the compressed spring 43 at its rear end, and between its forwardly extending forks carries the rotatable idler roller 62 upon the track frame 20. The track comprises joined links including those shown at 71, and prior to such adjustment of the rod is preferably in its operative position embracing the rollers 8 and 62, and the rolls, including rolls 24 to 27, inclusive, the tractor then being supported on the track by said rolls. The fork for each track unit is slidably mounted upon ,the track frame, integral retaining flanges 32 and 33 thereof of channel form depending from the body of the fork on both sides thereof,and embrace a pair of parallel longitudinally extending guide bars and 81, pref erably formed of a good quality of steel,

which are each bolted by a plurality of spaced machine screws 34, rigidly to the two lateral flanges 30 and 42, respectively, of the track frame.

With the above parts in place and with the track having the proper amount of slack for most efficient operation the threaded thrust rod is advanced so that its pointed end 86 enters the centering recess 87 of the disk 39. Preferably, the adjustment is so made that no substantial thrust effort is exerted by the rod upon the fork 35 through the compressed spring, sufficient to unseat the under side of the bolt head 41, after adjustment of the thrust rod and during non-use of the tractor.

The embodiment of my invention illustrated in Figs. 4, and 6 will now be readily understood, the structure being quite similar.

- disp acement of the fork elements and track frames; Each of the fork element flanges 92 are slotted longitudinally as shown at 97,

'andspaced bolts'98 are provided extending through opelrliings of the track frame flanges aligned wit' the slots, and together with washer springs 99, effect clamping of the fork element 93 upon the track frame. "Theuse of the washer springs reduces the tendency of the bolts to loosen.

Except for the different means adopted in the two described embodiments to join the Qfork element to the tractor frame so as to permit relative longitudinal movement, the

I two embodiments operate similarly.

l In the said embodiments, whenever a rock or other foreign object is lodged between the rolls or rollers and the track, there will be a ulling stress exercised u on the'track t'endmgfto break it, and to orce the rolls and rollers inwardly, tending to break therolls or theirsu pportsa Often in such exigency, such a foreign ob 'ectis crushed before break ing strains are e ected bythe stresses set up.

-. 40 However, in the embodiments of my inven-- tion described herein, whenever the stresses set up tend to become sufliciently powerful to endanger the mechanism, the forks will move rearwardly upon the flanged track frames," and" the compressive stress exerted upon the'already powerfull compressed helical s rings, such as that own at 43, Fig. 3, an 43, Fig. 5, will compress the spring 7 I to relieve the increased stresses. At such a 59 time, the head of the bolt 38 or 37 for the 7 different embodiments, will be spaced from,

the yoke portion of the fork'.

Such additional compression is only had in case of need. The normal compression of the thrust sprin is made so that they will yield further su ciently to avoid the setting up of breaking strains with a safety margin.

Having thus described my invention as.

applied in two embodiments,-I am aware that u numerousand extensive departures may be made from the embodiments herein illustrated anddescribed without'departingfrom the spirit-of my invention. f

Iclaim: I c5 1. In a traction device for tracklaying 6. A traction device for tracklayingrtractractors, a frame member, an endless track encircling said frame a oompreSsible coiled s ring carried by said i er structure mounted upon'saidframe in- V termediate the free .end of said spring and 7 said endless track", and means for restraining the spring from exerting any pressureonthe idler structure in its normal engagementwith said endless track.

2. In a traction device for tracklaying tractors a frame member, an endless track encircling said frame, an idler structure slidably associated with said frame, compressible means associated with said frame and idler structure, and means for restraining the compressible means from exerting-anypressure on the idler structure in its normal engage-" ment with said'end'less track;

3. In a traction device for tracklaying tractors, a frame member, an endless track encirclin said frame, an idler structure slidable at the orward end of said frame, compressible means resisting the rearward movement of said idler structure, and means for re-' straining the compressible means from exerting any pressure on the idler structure in its normal, engagement with said endless track.

.4. In a traction device for tracklaying tractors, a frame member an endless track encircling said frame, an i er structure slidable on said frame,-a compressible element as-- sociated with said idler structure, means for restraining the, compressibleelet'iient from exerting any pressure ontthe idler structure in its normal engagement witlfthe track and means foradjustingtheposition of said compressibleeleinent longitudinally of said frame without altering the normal functioning thereof. a

5. In a traction device for tracklaying tractors, a frame member, an endless track encircling said member, an idler structure slidably mounted upon said frame member, said structure including an idler supporting a portion of said endless track, compressible means associated with said idler structure, and means for restraining the compressible means from exertin any pressure on the idler struciniii: norma engagement with said endless trac tors, aframe member, an endless track encircling said member, an idler structure slid- .ably mounted upon said frame member, said structure including an idler supportinga portion of said, endless track, a compressible element associated with said idler structure, means for restraining the compressible element from exerting any pressure on the idler structure in its normal engagement with said 126 endless track, and means frictionally resisting any sliding movement of said idler struc- I ture.

7. a traction device for tracklaying tractors, a frame member, an endless track frame, and a movable encircling said member, a yoke mounted to move longitudinally on the forward end of said frame, a rotatable idler carried by said yoke, said idler engaging and supporting said track in desired extended position, a compressible coil spring engaging the rear end of said yoke, restraining means for the spring to prevent the spring from exerting forward movement of the yoke and means for bodily adjusting the position of said spring longitudinally of said frame Without altering the relation thereof with said yoke.

8. In a traction device for track laying tractors, a frame member, an endless track encircling said frame, an idler structure movably mounted on said frame, compressible means associated with and resisting the rearward movement of said idler structure, means for restraining the compressible means from exerting any pressure on the idler structure in its normal engagement with said endless track, and means for adjusting the position of said idler structure with respect to the endless track without altering the normal functioning of the compressible means.

In testimony whereof I hereunto affix my signature.

ROLLIN H. WHITE. 

